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Integrating Homogeneous and Heterogeneous Catalysis in a Copper Nanocluster with Lewis Acid–Base Sites for Chemical Conversion of CO_(2) and Propargylamine

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CCS Chemistry 2024年第9期6卷 2131-2141页

作者： Wan-Zhen Qiao Yu-Jue wang Si Li Rui wang Jie Wu Shuang-Quan Zang Henan Key Laboratory of Crystalline Molecular Functional Materials Henan International Joint Laboratory of Tumor Theranostical Cluster MaterialsGreen Catalysis and College of ChemistryZhengzhou UniversityZhengzhou 450001

It remains a significant challenge to develop a catalyst that merges the advantages of homogeneous and heterogeneous catalysis with high reactivity and great ***,an atomically precise Cu_(6)-NH_(2) nanocluster with distorted octahedral Cu_(6) core and NH_(2)-functionalized ligands has been developed as the first homo/heterogeneous catalyst to catalyze the cyclization reaction of propargylic amines with carbon dioxide(CO_(2))under mild *** a homogeneous catalyst,Cu_(6)-NH_(2) shows excellent catalytic activity with high turnover frequency due to highly accessible active *** definite coordination geometry and homogeneity nature of active centers make it convenient to investigate the structure–activity relationship at the atomic level through experiments and theory *** addition,the nanocluster exhibits excellent stability,great recrystallizability,and reusability in five catalytic cycles,in which its catalytic performance has no obvious ***,Cu_(6)-NH_(2) incorporates Lewis acid and base sites in metal and ligand,respectively,which can promote catalytic efficiency in a synergistic effect in the absence of any ***,Cu_(6)-NH_(2) can realize direct conversion of CO_(2) in simulated flue gas into oxazolidinones with high *** metal-ligand cooperative effect and integrated advantages of homogeneous and heterogeneous catalysis would provide new perspectives to achieve advanced metal nanocluster catalysts for CO_(2) conversion.

关键词： copper nanocluster atomically precise structure Lewis acid-base sites CO_(2)cyclization reaction cocatalyst-free

Epigenetics and environmental health

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Frontiers of Medicine 2024年第4期18卷 571-596页

作者： Min Zhang Ting Hu Tianyu Ma Wei Huang Yan wang Key Laboratory of Cancer and Microbiome State Key Laboratory of Molecular OncologyNational Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing100021China Beijing Key Laboratory of Cancer Invasion and Metastasis Research Department of Biochemistry and Molecular BiologySchool of Basic Medical SciencesCapital Medical UniversityBeijing100069China

Epigenetic modifications including DNA methylation,histone modifications,chromatin remodeling,and RNA modifications complicate gene regulation and heredity and profoundly impact various physiological and pathological *** recent years,accumulating evidence indicates that epigenetics is vulnerable to environmental changes and regulates the growth,development,and diseases of individuals by affecting chromatin activity and regulating gene *** exposure or induced epigenetic changes can regulate the state of development and lead to developmental disorders,aging,cardiovascular disease,Alzheimer's disease,cancers,and so ***,epigenetic modifications are *** use of specific epigenetic inhibitors targeting epigenetic changes in response to environmental exposure is useful in disease ***,we provide an overview of the role of epigenetics in various ***,we summarize the mechanism of epigenetic alterations induced by different environmental exposures,the influence of different environmental exposures,and the crosstalk between environmental variation epigenetics,and genes that are implicated in the body's ***,the interaction of multiple factors and epigenetics in regulating the initiation and progression of various diseases complicates clinical *** discuss some commonly used epigenetic drugs targeting epigenetic modifications and methods to prevent or relieve various diseases regulated by environmental exposure and epigenetics through diet.

关键词： epigenetics environmental exposure health prevention and therapy

Therapeutic potentials of peptide-derived nanoformulations in atherosclerosis:present status and future directions

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International Journal of Smart and Nano Materials 2024年第3期15卷 610-651页

作者： Xue Liu Weijiao wang Qiang Li Hongtao Niu Weili Zhang Department of Cardiovascular Medicine Yantaishan HospitalYantaiChina Department of Otolaryngology Yantaishan HospitalYantaiChina Department of Geriatric Medicine Yantaishan HospitalYantaiChina

Atherosclerosis is a severe cardiovascular disease followed by the accumulation of atherosclerotic plaques within the lumen of blood vessels resulting in reduced blood flow thus initiating a series of *** therapies for atherosclerosis encounter multiple chal-lenges,especially difficulty in precisely concentrating in certain affected regions and the potential for unwanted side ***,scientists are focused on developing nanoformulations for atherosclerosis diagnosis and ***-based nanomedi-cines improve conventional therapies by offering improved structural and therapeutic stability and enabling target-specific *** inherent biocompatibility and biodegradability additionally render them desirable materials intended for in vivo *** review manu-script aims to provide an in-depth overview of peptide-based nano-medicines for atherosclerosis,focusing on targeted cells like endothelial cells,macrophages,and monocytes and their interaction with different plaque ***,the manuscript also highlights the latest progress in multimodal techniques and provides a comprehensive overview of limitations associated with their practical implementation.

关键词： Atherosclerosis anti-atherosclerotic drugs bioavailability peptide-based nanomedicines drug targeting

Construction of remote cyano-substituted quaternary carbon centers via nickel-catalyzed migratory hydrocyanation of unconjugated dienes

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Science China Chemistry 2024年第10期67卷 3397-3405页

作者： Yidan Xing Rongrong Yu Mingdong Jiao Ting wang Xianjie Fang Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Key Laboratory of Organosilicon Material Technology of Zhejiang ProvinceCollege of MaterialChemistry and Chemical EngineeringHangzhou Normal UniversityHangzhou 311121China Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs School of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The transition-metal-catalyzed migratory functionalization has emerged as a robust protocol for the building of C–C bonds remote from the“initiation”***,a similar strategy for the construction of quaternary carbon centers is still underdeveloped and only a limited number of reports ***,we report a nickel-catalyzed migratory hydrocyanation of unconjugated dienes to construct remote cyano-substituted quaternary carbon *** transformation features exceptional regioselectivity,mild reaction conditions,broad substrate scope and high *** synthetic utility of this method has been highlighted by a series of product derivatizations,and the potential of this transformation has been extended to synthesize TRPV1 antagonist and the key intermediate in the total synthesis of *** functional theory(DFT)studies unveiled that the specific catalytic pocket assumed a significant role in the selective formation of cyano-substituted quaternary carbon centers.

关键词： chain-walking regioselectivity remote cyanation quaternary carbon centers unconjugated dienes

Detection Algorithm of Laboratory Personnel Irregularities Based on Improved YOLOv7

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Computers, Materials & Continua 2024年第2期78卷 2741-2765页

作者： Yongliang Yang Linghua Xu Maolin Luo Xiao wang Min Cao School of Electrical Engineering Guizhou UniversityGuiyang550025China

Due to the complex environment of the university laboratory,personnel flow intensive,personnel irregular behavior is easy to cause security *** using mainstream detection algorithms suffers from low detection accuracy and slow ***,the current management of personnel behavior mainly relies on institutional constraints,education and training,on-site supervision,etc.,which is time-consuming and *** the above situation,this paper proposes an improved You Only Look Once version 7(YOLOv7)to achieve the purpose of quickly detecting irregular behaviors of laboratory personnel while ensuring high detection ***,to better capture the shape features of the target,deformable convolutional networks(DCN)is used in the backbone part of the model to replace the traditional convolution to improve the detection accuracy and ***,to enhance the extraction of important features and suppress useless features,this paper proposes a new convolutional block attention module_efficient channel attention(CBAM_E)for embedding the neck network to improve the model’s ability to extract features from complex ***,to reduce the influence of angle factor and bounding box regression accuracy,this paper proposes a newα-SCYLLA intersection over union(α-SIoU)instead of the complete intersection over union(CIoU),which improves the regression accuracy while increasing the convergence *** experiments on public and homemade datasets show that the improved algorithm outperforms the original algorithm in all evaluation indexes,with an increase of 2.92%in the precision rate,4.14%in the recall rate,0.0356 in the weighted harmonic mean,3.60%in the mAP@0.5 value,and a reduction in the number of parameters and *** with the mainstream algorithm,the improved algorithm has higher detection accuracy,faster convergence speed,and better actual recognition effect,indicating the effectiveness of the improved algorithm in this p

关键词： University laboratory personnel behavior YOLOv7 deformable convolutional networks attention module intersection over union

A new fluorocarbon adhesive:Inhibiting agglomeration during combustion of propellant via efficient F-Al_(2)O_(3) preignition reaction

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Carbon Energy 2024年第6期6卷 292-305页

作者： Qifa Yao Min Xia Chao wang Fanzhi Yang Wei Yang Yunjun Luo School of Materials Science and Engineering Beijing Institute of TechnologyBeijingChina Key Laboratory of High Energy Density Materials Ministry of EducationBeijing Institute of TechnologyBeijingChina School of Aerospace Engineering Beijing Institute of TechnologyBeijingChina Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijingChina

Inhibiting the agglomeration of molten aluminum particles packed in the binder network is a promising scheme to achieve efficient combustion of solid *** this investigation,the hydroxyl-terminated structured fluorinated alcohol compound(PFD)was introduced to modify the traditional polyethylene glycol/polytetrahydrofuran block copolymerization(HTPE)binder;that is,a unique fluorinated polyether(FTPE)binder was synthesized by embedding fluorinated organic segments into the HTPE binder via crosslinking *** FTPE was applied in aluminum-based propellants for the first *** to the complete release of fluorinated organic active segments in the range of 300℃to 400℃,the burning rate of FTPEbased propellant increased from 4.07(0%PFD)to 6.36 mm/s(5%PFD),increased by 56.27%under 1 *** reaction heat of FTPE propellants increased from 5.95(0%PFD)to 7.18 MJ/kg(5%PFD)under 3.0 MPa,indicating that HTPE binder modified with PFD would be conducive to inhibiting the D90 of condensed combustion products(CCPs)dropped by 81.84%from 75.46(0%PFD)to 13.71μm(5%PFD)under 3.0 MPa,in consistent with the significant reduction of aluminum agglomerates observed on the quenched burning surface of the *** results demonstrated that a novel FTPE binder with PFD can release fluorinated organic active segments,which motivate preignition reaction with the alumina shell in the early stage of aluminum combustion,and then enhance the melting diffusion effect of aluminum to inhibit the agglomeration.

关键词： agglomeration characteristics aluminum particles combustion fluorine alcohol compounds HTPE propellants

Soil conditioning of clay based on interface adhesion mechanism:Microscopic simulation and laboratory experiment

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Underground Space 2024年第5期18卷 239-255页

作者： Yong Fang Bin Zhuo Ruyue Zhang Yubo wang Liupan Dou Yuxiang Yao Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China

Clogging frequently occurs in the cutter head,excavation chamber or screw conveyor when an earth pressure balance(EPB)shield machine is tunneling in soft or silty clay ground with high clay mineral *** this paper,montmorillonite,kaolinite,and illite were selected as research objects,and molecular dynamics simulation and laboratory experiment were *** the microscopic scale,dynamic contact behavior and interfacial mechanical behavior of the interface between clay minerals and water/surfactant solution was simulated and the interfacial adhesion and conditioning mechanism between clay minerals and water/surfactant solution was ***,sodium dodecyl benzene sulfonate surfactant was selected as the main composition of the soil ***,the adhesion stress before and after soil conditioning and the contact angles between clay minerals and water/surfactant solution were tested and analyzed at the macroscopic *** result shows that the contact angle between droplet and clay mineral surface is an important parameter to characterize soil *** simulation rules of the microscopic contact angle are consistent with the experiment ***,the adsorption energy between microscopic substances is dominated by electrostatic force,which can reflect the adhesion stress between macroscopic *** adhesion stress can be effectively decreased by adding the surfactant to the soil conditioner.

关键词： EPB clogging Clay minerals Microscopic simulation Mechanism analysis Laboratory experiment Adhesion stress

Two-stage aging treatment to accelerate aging kinetics without impairing strength in B_4C/7A04Al composite

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Science China(Technological Sciences) 2024年第8期67卷 2485-2492页

作者： CHEN YunTao MA GuoNan ZHU ShiZe wang Dong XIAO BoLv MA ZongYi Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Centre of Excellence for Advanced Materials Dongguan 523808China

Aging treatments are the key process to obtain satisfactory strength for 7xxxAl alloys and their composites. However, traditional single-stage(SS) aging is time-consuming to reach a peak strength condition. In this study, an efficient 120℃ + 160℃ two-stage(TS) aging treatment was proposed on a B_4C/7A04Al composite fabricated via powder metallurgy(PM) technology, which could acquire similar peak-aging strength but only took about 15% of the time compared to traditional 120℃ SS aging. The evolution of precipitation during the TS aging was investigated, as well as those of the 7A04Al alloys for comparison. In the second stage aging process, the higher aging temperature accelerated the nucleation of η′ phases inside the grains and thus increased the density of precipitates. Moreover, the short aging time limited the coarsening of precipitates and the broadening of precipitatefree zones. The above factors were beneficial for quickly obtaining satisfactory precipitation strengthening effects. The B_4C/7A04Al composite exhibited slower aging kinetics than the 7A04Al alloy in the TS aging. Mg elements consumption by the chemical reaction between B impurities introduced by B_4C particles and the Al matrix was considered to potentially retard the aging kinetics of the B_4C/7A04Al composite. Nevertheless, the precipitation sequence was not affected.

关键词： aluminum matrix composites aging treatment powder metallurgy mechanical properties precipitation

An Immune-Inspired Approach with Interval Allocation in Solving Multimodal Multi-Objective Optimization Problems with Local Pareto Sets

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Computers, Materials & Continua 2024年第6期79卷 4237-4257页

作者： Weiwei Zhang Jiaqiang Li Chao wang Meng Li Zhi Rao College of Computer Science and Technology Zhengzhou University of Light IndustryZhengzhou450001China Technology Research and Development Center Jilin Tobacco Industry Company LimitedChangchun130031China College of Tobacco Science and Engineering Zhengzhou University of Light IndustryZhengzhou450001China Raw Material Department Hongyun Honghe Tobacco(Group)CompanyKunming650202China

In practical engineering,multi-objective optimization often encounters situations where multiple Pareto sets(PS)in the decision space correspond to the same Pareto front(PF)in the objective space,known as Multi-Modal Multi-Objective Optimization Problems(MMOP).Locating multiple equivalent global PSs poses a significant challenge in real-world applications,especially considering the existence of local *** identifying and locating both global and local PSs is a major *** tackle this issue,we introduce an immune-inspired reproduction strategy designed to produce more offspring in less crowded,promising regions and regulate the number of offspring in areas that have been thoroughly *** approach achieves a balanced trade-off between exploration and ***,we present an interval allocation strategy that adaptively assigns fitness levels to each *** strategy ensures a broader survival margin for solutions in their initial stages and progressively amplifies the differences in individual fitness values as the population matures,thus fostering better population ***,we incorporate a multi-population mechanism that precisely manages each subpopulation through the interval allocation strategy,ensuring the preservation of both global and local *** results on 21 test problems,encompassing both global and local PSs,are compared with eight state-of-the-art multimodal multi-objective optimization *** results demonstrate the effectiveness of our proposed algorithm in simultaneously identifying global Pareto sets and locally high-quality PSs.

关键词： Multimodal multi-objective optimization problem local PSs immune-inspired reproduction